Gear pump



Oct. 9, 1945. e. w. MULLER GEAR PUMP Filed March 7. 1942 2 Sheeis-Sheet1 mm 4 m n 4 1m 4 Z a Oct. 9, 1945. s. w. MULLER GEAR PUMP Filed March7. 1942 2 Sheets-Sheet 2 ,lnventor: 652A WALTER 'MZ/ZLER members of thea pump Patented Oct- 9, 1945 NI ED STAT G za WalterMiiller', Bron,France; vested Alien Property Custodian Application March '1. 1942, s miNo. 433,808

Iii-France February20,194'1 3 a "7, Claims. (01, 103-126) The presentinvention relates to gear pumps;

and more particularly to such gear pumps as are used industrially fordisplacing viscous fluids.

for example fluids of this category {employed .for

spinning artificial textile filaments andthreads,

and as are generally interposed between a master pressure pump and thespinning dies,- the'chiet function or such gear pumps being toregulatethe rate of delivery of the fluid.- j v An object of the invention is toprovide-'ior omarumr' ing recesses tor 'theigearsan v lineating andclosingthe-pumpj'bodmy as P Taur nure? 7 Figures 2 and 3Ia reelevational 'views sliowln the side plates.

theaforesaid and like 'uses' a gear pump having such an improvedconstruction as; to fulfill practical requirements under, betterconditions than similar p'umpsas used-heretofore. v

Another object d! the invention is to provide animproved gear pump thestructure of ,.which is so devised as to cause the' whole or the -fiuidflowing therethrough to perform during operatiiin lubrication of atleast some of the revoluble and particularly ofxthe gear shafts.

Another object er the invention is'to erase a gear pump having such animproved structure as to damp away, the fluid pulsations'therebyenhancing the steadiness in the rate of flow of the liquid and ensuringbetter spinning conditionswhen said liquid is used for the production ofartificial textile filaments or threads.

A further object of the invention is to provide a gear pump of suchimproved construction as to enable the fluid -to.:circulate therethroughdirectly without'being hindered or throttlcd and without any whirling orstopping efiectrthereby avoiding such sedimentations as might other wiseclog up the circuit or interfere with-proper spinning conditions. a

A still further object of the invention (is to I provide an improvedgear pum'pfoi simple and rugged construction particularly,wellsuited forthe handling of viscousliquids used in'the production of artificialtextile'filaments and threads and comprising self-contained means"ensuring automatic flushing lubrication by the'li'quid itself and atthe siimetime great regularity. of flow;

With these and such other objects in view as will incidentally appearhereinafter, thefmven tion comprises the novel construction, combin'a 0fFig; 5.

-Figure 4 is a sideiviewi showin'g thefpcdy plete 'mgurej rise se' Likereference characters f throughout the severalviews.

invention illus trated in the urawing s aigar-punip specially' adaptedfor the handling of 'iviscous liquids 1 adapted. to bespun intofilaments.or' threads such for example was; viscose; acetate; cupro-'textile;artificial wool' orthe iike-.:

Advantageously the pump body comprises. a I 'Vmiddle or bodylplate=- lformed with a jpainof 1 circular recesses",:2'i-'in"which.-the gears --8.are

snugly. f eceivedg i The midd e '-'-1 11a=- ,-1 isl d and delineatedsidewise-by a pair of side-plates-l 5through whichiar'erevolubly-engagedtmP n 6,;61-carryingthe respective g'ear's 3.;1--

the suction duet a-ahd thedeuivery duct-'9' tithepump. The''ducts.'8,:9preferably have their ages I e at right-angles to thegear-carrying fuin's'and have openings a, b. c,,d;w'hich-communicatewith' the holes in the' side plates}; 5v through which Theside plates 4,;5 .ar'eihollowed to provide Communication betweerigthesuction duct 8 the delivefrydu t The chamber Hispreferably formed in a91 arate front'bracketiifljwhile the duct I l is formed. in a rearzplate-i it; said bracket; and plate being boltedorotherwise'fixdlysecured t the "side tion and arrangement of parts-that willnow-bedescribed with reference to the accompanying" diagrammatic drawingsexemplifying thesame and forming a part of the present disclosure,

In the drawings: I 1 Figure 1 is a vertical sectional in its entirety animproved gear pump 'ac'corde ing to the invention comprising a bodyplatezhav-g plates. .5- andpum'pzniiddleiplatei l.- p

as shown ran e-re m a, there. is eeveetageouslyinterppsedbn' thedelivery.duct V9 in- .termediate the holes for; the I.Din$. i 6, his. ring orwasher 2ll 'having'an. annular. groove 2 IV commuview showing nicating-With said-duct" 9,: The ring; or was-her 20 maybe axiallybored tuprovide the duct i3 whichcommun-ica'tes with the delivery chamber 19 *ofthe-pump andj'a oawuh theductl4.

The path of the liquid through the apparatus shown in the drawings is asshown by the arrows and may be described as follows:

The liquid sucked in by the pump enters the apparatus through the inletaperture 22 and flows through the duct I, then successively contests or"licks" the front ends of the pins 0, 61 wherethey are joumalled in theside plate 4.

I Thereafter the liquid enters the annular chamber ll through the duct land penetrates into the suction chamber ll of the pump through the ductII. The liquid forced out of the delivery chamber l9 enters the duct Ithrough the duct I3 bored in the ring 20 and then penetrates into theduct 9 through the duct I 5. After contacting and flushing the part ofthe pin 61 journalled in the side plate and flowing through the groove2| in the ring (see Fig. 2) the liquid contacts or "licks" the part ofthe pin 6 journalled in the side plate 5 and is discharged through theoutlet aperture 23.

It will be seen that the whole of the liquid moved by the pump can thuscontact or flush both ends of the gear-carrying pins 6, 61 where theyare journalled in the side plates 4, 5.

Alternatively, the following constructional arrangements may be adopted:a v

The gears 3 may be so mounted or splined upo their operating pins 6, 61as to float" upon them, the driving feathers housed in said pinscoacting with grooves 26 formed in the bore of said gears 3 so that noaxial thrust can be transmitted to these gears.

In order to provide for the required degree of liquid tightness on thatside where the in 81 is driven by the outer control shaft 21, elasticgasket 28 is provided so as to seal the chamber I l on the front side.As shown in Fig. 1, said gasket comprises a U-shaped annulus and may bemade for example of synthetic rubber.

Furthermore, owing to the fact that it contacts with the pumped fluid,said elastic gasket has the supplementary effect of damping thepulsations and of avoiding irregularities in the delivery flow from thepump.

In the constructional form shown, the gasket 28 is abutted against awasher 29 having a tight fit in a shouldered portion of the frontbracket II.

In order to improve said damping effect of the gasket 28, it isadvantageous to provide the latter with grooves in one at least of thecontact walls between said gasket and the washer 29. Preferably, thesegrooves having a suitable shape, for example a circular (grooves 281,Fig. 7) shape, will be situated in the bottom wall of said gasket 28.

The shaft 21 which may be connected to the pin '1 in any approved waydrives the latter advantageouslyv as illustrated in Fig. 1 owing toco-action between grooves 30 in the rear end of said shaft and a key orcotter 3| set through the pin 81. The sectional area of the key orcotter 3| is preferably reckoned so that in case of jamming or of anyabnormal resistance occurring in the pump operation, said key orcotterJl should be sheared, therebyprotecting the rest of the mechanismagainst any such undue stress as might otherwise seriously damage themost costly parts of the apparatus.

In accordance with another alternative feature of the invention, theshaft 21 is independently lubricated, for example by means of alubricator 32 having a screw-threaded reduced shank engaged through ahole tapped in the bracket II, the extremity of said shank being incommunication with a groove 33 in said shaft so as to hold the latter inproper longitudinal position.

Moreover, according to a particularly advantageous arrangement, thesuction chamber ll and delivery chamber is formed in the middle plate Iare defined by walls extending askew and generated by the intersectionof an oblique cylinder (as shown in chain lines in Fig. 6) or a skewprism with the cylindrical recesses 2 in which the gears 2 areaccommodated, the geometrical axis Y-Y of said cylinder or prism beingsituated in the plane of tangence X-X of the pitch circles e of thegears I and passing through the point of contact 0 of the pitch circleslocated in the mean plane of said gears. The degree of slant of thoseedges which define the suction chamber l8 and the delivery chamber ISwith respect to the gear teeth should be preferably so selected as tocause the nicks of two consecutive teeth to be continuously incommunication with said chambers I8, I 9. The purpose of thisarrangement is to regularize the rate of delivery of the pump.

According to a further alternative constructional form, regularity ofthe rate of delivery may be still further improved (this being of theutmost importance for spinning) by interposing either on the suctionduct or preferably on the delivery duct of the pump a second resilientdamping member such as a rubber pad or stopper 34 arranged in the end ofthe duct 9 and providing for the resilient material of which it is madean accurately bored recess 35. Said stopper 3! is fitted on a cap plate36 fixed to the side plate 5 by means of a screw 31.

It will be seen that owing to the foregoing construction, the severalobjects of the invention are fulfilled inasmuch as it becomes possibleby simple and cheap manufacturing means to provide a self-lubricatinggear pump using the pumped liquid as a lubricating medium and possessinggreat regularity of rate oigliquid delivery, thereby ensuring a majoradvantage particularly where the pump is intended to feed liquid tospinning dies in the production of artificial textile materials.

Minor constructional details might be varied of course without departingfrom the ambit of the subioined claims.

What I claim is:

1. A gear pump comprising in combination a pump body constituted by atleast a body part and a side part adapted to be juxtaposed to each otherby one face, two recesses hollowed in said body part in said face, twopump gears housed in said recesses, holes in said parts, carrier pinsfor said gears journalled in said holes, one of said pins projectingoutside the outer face of said side part, a fluid circuit through saidpump, a bracket juxtaposed to said outer face of said side part, anexcavation provided in said bracket, said excavation being adjacent tosaid outer face and I coaxial with the projecting one of said carrierpins, a gasket of elastic material in said excavation, a path hollowedin said gasket round said carrier pin and forming a portion of saidfluid circuit.

2. A gear pump comprising in combination a body plate, side platesjuxtaposed to the side faces of said body plate, two recesses hollowedthrough said body plate, two pump gears housed in said recesses, holesin said side plates, carrier pins for said gears journalled in saidholes, one of said pin projecting outside the outer face of one sideplate, suction and delivery chambers formed on either side of theintermeshing region of said gears, a fluid circuit through said pumpcomprising suction and delivery ducts respectively in said side plates,each of said ducts being straight, openings for establishingcommunication between each duct and respectively each of the holessituated on the same side as the corresponding duct with respect to thegears, channel means connecting each of said ducts with respectivelysaid suction and delivery chambers, a. bracket juxtaposed to said outerface of said side plate through which a carrier pin projects, a circularexcavation provided in said bracket, said excavation being ad acent tosaid outer face and coaxial with the projecting one of said carrierpins, a gasket of elastic material in said excavation having a pathhollowed therein encircling said carrier pin and forming a part of thecorresponding one of said channel means, and means journalled in saidbracket for rotating said pump gears.

3. A gear pump comprising in combination a body plate, side bodiesjuxtaposed to the side faces of said body plate, two recesses in saidbody plate, two pump gears journalled in said side bodies for rotationin said recesses, means for driving said pump gears, a fluid circuitthrough said pump comprising suction and delivery ducts respectively ineach of said side bodies and suction and delivery chambers in said bodyplate, said chambers being defined on either side of the intermeshingregion of said gears by walls forming part of a slanting surface ofrevolution whose axis is sensibly contained in the plane of tangency ofthe gear pitch circles and passes sensibly through the point at whichsaid circles contact in their mean plane, the angle of said axis with'said mean plane and the radius of said surface of revolution beingadapted so as to make each of said chambers communicate continuously atleast with one nick between a pair of consecutive teeth.

4. A pump gear according to claim 1 further comprising grooves in thesurface of said gasket by which the gasket contacts with the wall ofsaid excavation.

5. A gear pump comprising a body plate having gear-receiving recessesand suction and delivery chambers located on either side of the gearingregion, meshing gears housed in said recesses and having projectingcarrier'pins, a pair of side plates juxtaposed to the side faces of thebody plate and so hollowed as to provide suction and delivery ducts,channel means establishing communication between the suction duct andchamber and between the delivery chamber and duct, the side plateshaving at right angles to their duct holes in which are journalled saidpins, the peripheries of said holes being arranged so that the suctionand delivery ducts are tangential thereto to cause the pumped fluidpassing through said ducts to lightly lick and lubricate said pins.

6. A gear pump comprising a body plate having gear-receiving recessestherein, pump gears housed in said recesses and having projectingcarrier pins, means for rotating said pump gears, and a pair of sideplates on opposite sides of the body plate provided with apertures forjournalling the projecting portions of said carrier pins, and alsohaving suction and delivery ducts therein. said ducts being arrangedtangential to said journal apertures whereby liquid passing through saidducts will lightly touch the periphery of said carrier pins while movingto and from the pump gears.

7. A gear pump as recited in claim 6, wherein resilient members areararnged in said ducts on opposite sides of said gears to cushion theflow of liquid.

GEzA WALTER MULLER.

